u-boot/board/trab/rs485.c
C Nauman d9abba8254 Add generic support for samsung s3c2440
This patch adds generic support for the Samsung s3c2440 processor.

Global s3c24x0 changes to struct members converting from upper case to
lower case.

Signed-off-by: Craig Nauman <cnauman@diagraph.com>
Cc: kevin.morfitt@fearnside-systems.co.uk
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2010-10-28 15:35:56 +09:00

205 lines
4.6 KiB
C

/*
* (C) Copyright 2003
* Martin Krause, TQ-Systems GmbH, <martin.krause@tqs.de>
*
* Based on arch/arm/cpu/arm920t/serial.c, by Gary Jennejohn
* (C) Copyright 2002 Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <common.h>
#include <asm/arch/s3c24x0_cpu.h>
#include "rs485.h"
static void rs485_setbrg (void);
static void rs485_cfgio (void);
static void set_rs485re(unsigned char rs485re_state);
static void set_rs485de(unsigned char rs485de_state);
static void rs485_setbrg (void);
#ifdef NOT_USED
static void trab_rs485_disable_tx(void);
static void trab_rs485_disable_rx(void);
#endif
#define UART_NR S3C24X0_UART1
/* CPLD-Register for controlling TRAB hardware functions */
#define CPLD_RS485_RE ((volatile unsigned long *)0x04028000)
static void rs485_setbrg (void)
{
struct s3c24x0_uart * const uart = s3c24x0_get_base_uart(UART_NR);
int i;
unsigned int reg = 0;
/* value is calculated so : (int)(PCLK/16./baudrate) -1 */
/* reg = (33000000 / (16 * gd->baudrate)) - 1; */
reg = (33000000 / (16 * 38400)) - 1;
/* FIFO enable, Tx/Rx FIFO clear */
uart->ufcon = 0x07;
uart->umcon = 0x0;
/* Normal,No parity,1 stop,8 bit */
uart->ulcon = 0x3;
/*
* tx=level,rx=edge,disable timeout int.,enable rx error int.,
* normal,interrupt or polling
*/
uart->ucon = 0x245;
uart->ubrdiv = reg;
for (i = 0; i < 100; i++);
}
static void rs485_cfgio (void)
{
struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
gpio->pfcon &= ~(0x3 << 2);
gpio->pfcon |= (0x2 << 2); /* configure GPF1 as RXD1 */
gpio->pfcon &= ~(0x3 << 6);
gpio->pfcon |= (0x2 << 6); /* configure GPF3 as TXD1 */
gpio->pfup |= (1 << 1); /* disable pullup on GPF1 */
gpio->pfup |= (1 << 3); /* disable pullup on GPF3 */
gpio->pacon &= ~(1 << 11); /* set GPA11 (RS485_DE) to output */
}
/*
* Initialise the rs485 port with the given baudrate. The settings
* are always 8 data bits, no parity, 1 stop bit, no start bits.
*
*/
int rs485_init (void)
{
rs485_cfgio ();
rs485_setbrg ();
return (0);
}
/*
* Read a single byte from the rs485 port. Returns 1 on success, 0
* otherwise. When the function is succesfull, the character read is
* written into its argument c.
*/
int rs485_getc (void)
{
struct s3c24x0_uart * const uart = s3c24x0_get_base_uart(UART_NR);
/* wait for character to arrive */
while (!(uart->utrstat & 0x1))
;
return uart->urxh & 0xff;
}
/*
* Output a single byte to the rs485 port.
*/
void rs485_putc (const char c)
{
struct s3c24x0_uart * const uart = s3c24x0_get_base_uart(UART_NR);
/* wait for room in the tx FIFO */
while (!(uart->utrstat & 0x2))
;
uart->utxh = c;
/* If \n, also do \r */
if (c == '\n')
rs485_putc ('\r');
}
/*
* Test whether a character is in the RX buffer
*/
int rs485_tstc (void)
{
struct s3c24x0_uart * const uart = s3c24x0_get_base_uart(UART_NR);
return uart->utrstat & 0x1;
}
void rs485_puts (const char *s)
{
while (*s) {
rs485_putc (*s++);
}
}
/*
* State table:
* RE DE Result
* 1 1 XMIT
* 0 0 RCV
* 1 0 Shutdown
*/
/* function that controls the receiver enable for the rs485 */
/* rs485re_state reflects the level (0/1) of the RE pin */
static void set_rs485re(unsigned char rs485re_state)
{
if(rs485re_state)
*CPLD_RS485_RE = 0x010000;
else
*CPLD_RS485_RE = 0x0;
}
/* function that controls the sender enable for the rs485 */
/* rs485de_state reflects the level (0/1) of the DE pin */
static void set_rs485de(unsigned char rs485de_state)
{
struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
/* This is on PORT A bit 11 */
if(rs485de_state)
gpio->padat |= (1 << 11);
else
gpio->padat &= ~(1 << 11);
}
void trab_rs485_enable_tx(void)
{
set_rs485de(1);
set_rs485re(1);
}
void trab_rs485_enable_rx(void)
{
set_rs485re(0);
set_rs485de(0);
}
#ifdef NOT_USED
static void trab_rs485_disable_tx(void)
{
set_rs485de(0);
}
static void trab_rs485_disable_rx(void)
{
set_rs485re(1);
}
#endif